1. Field of the Invention
The invention concerns the production of ring collars of the type used in some diaphragm clutch mechanisms to provide an axial support to the diaphragm on the side opposite the axial support which is found at the bottom of the cover of such a mechanism.
These ring collars are in the shape of a truncated cone overall.
2. Description of the Prior Art
To produce ring collars it is possible, for example, to cut and stamp a metal blank.
But the corresponding production method leads, expensively, to large amounts of waste, notably on the inside of the ring collar obtained.
It is also possible to cut and stamp a tube.
But this production involves, in an equally expensive manner, the prior production of such a tube, and if this is a blind tube, there is still a considerable amount of waste at the corresponding end of the latter.
The object of the invention is a more economical production method.
Relating, therefore, to the production of a ring collar, this method is characterised in that, stating with a metal strip, this strip is wound helically, a length corresponding to one pitch of the helix is cut from this strip, the two ends of this length are acted upon axially in such a way that they are brought opposite one another, the two ends thus aligned are welded to one another so as to obtain a cylindrical ring, and this ring is formed into a truncated cone.
All these operation, which advantageously involve no waste, can advantageously be executed one after the other on the same machine.